Multiple-mode elevator car system



J. suozzo MULTIPLE-MODE ELEVATOR CAR SYSTEM Feb. 5, 1957 7 Sheets-Sheet 1 Filed, March 17, 1954 Fig.2.

0 2 Z T 0 N E s N h o J ATTORN EY Feb. 5, 1957 J. suozzo 2,780,314

MULTIPLE-MODE ELEVATOR CAR SYSTEM Filed March 17, 1954 7 Sheets-Sheet 4 Fig.4.

Feb. 5, 1957 J. suozzo MULTIPLE-MODE ELEVATOR CAR SYSTEM 7 Sheets-Sheet 5 Filed March 17, 1954 QO E my $5M mv mmam e mmDm Fig.4A.

Feb, 5, 1957' J. suozzo MULTIPLE-MODE ELEVATOR CAR SYSTEM 7 Sheets-Sheet 6 Filed March 17, 1954 United States Patent 0 MULTIPLE-MODE ELEVATGR CAR SYSTEM John Suozzo, Paramus, N. 5., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa, :1 corporation of Pennsylvania Application March 17, 1954, Serial No. 416,872

18 Claims. (Cl. 187-49) This invention relates to elevator systems having multiple modes of operation and it has particular relation to an elevator system employing a single car arranged for multiple-mode operation.

Certain aspects of the invention are suitable for an elevator system employing a number of elevator cars arranged in a bank. However, the invention is particularly suitable for an elevator system employing only a single elevator car and may be described adequately with respect to a single car system.

In accordance with the invention an elevator system employing a singlecar may have plural modes of operation. For example, in one mode of operation the elevator cars may provide similar service for all floors of a building or structure. In a second mode of operation the elevator car may provide preferred operation for certain floors of the building.

In a preferred embodiment of the invention as applied to a single elevator car the car may be parked at a parking floor when no call for elevator service remains to be answered. This parking floor may be a terminal floor or an intermediate floor. If desired, different parking floors may be selected for different periods of the day. It will be assumed that the parking floor is a terminal floor. In response to registration of one or more calls for elevator service the elevator car is started from the parking floor and stops at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car. If the elevator car leaves the parking floor in a first direction preferably it stops and reverses at the farthest floor for which a call is registered requiring travel of the elevator car in a second direction provided no call is registered requiring further travel of the elevator car in the first direction.

Although the elevator car may be started from each of the floors at which it stops in response to a manual operation by a car attendant, preferably the elevator car is arranged for operation without an attendant. When so arranged the elevator car automatically starts from each floor at which it has stopped for a predetermined time as long as a call for elevator service remains to be answered.

The transfer between modes of operation preferably is effected in response to a traffic condition. Thus registration of a predetermined number of calls for elevator service from certain of the floors or registration of a number of calls for elevator service which have been registered for a substantial period of time from certain of the floors may be employed for the purpose of initiating the transfer operation.

In a preferred embodiment of the invention the transfer is elfected in response to a loading of the elevator car to capacity While set for travel in a predetermined direction. This registration may be effected by a manual operation but preferably is effected by a load-weighing device. If such loading occurs at one of the higher floors of a building while the elevator car is set for down travel 2,730,314 Fatentzed Feb. 5, 1957 of the elevator car may be assigned on its next upward trip to stop and reverse at a lower floor for the purpose of providing reasonably well distributed elevator service for the various floors of the building. Under certain conditions the elevator car may be assigned to by-pass calls registered from certain floors in order to expedite service for other floors of the building.

As previously pointed out, the elevator car preferably starts from a floor at which it has stopped only after the expiration of a substantial time. This permits normal loading and unloading of the elevator car at a floor before it is assigned to leave such floor. The invention further contemplates the variation of the lapse of time required before an elevator car can leave a floor at which it is stopped.

It is therefore an object of the invention to provide an improved elevator system having plural modes of operation.

It is a further object of the invention to provide an elevator system employing a single elevator car having plural modes of operation.

It is also an object of the invention to provide an elevator system employing a single car which provides similar service for a number of fioors of a building and which under predetermined conditions'provides a preferred service for part only of such floors.

it is an additional object of the invention to assign an elevator car to provide service for predetermined floors of a building on its next trip when a predetermined traffic condition occurs while the elevator car is positioned at floors spaced from such assigned floors.

It is another object of the invention to provide an elevator system employing a single elevator car which is parked at a parking floor in an absence for a call for service, which during call registration provides similar service for a number of floors of the building, and which upon occurrence of a predetermined traffic demand in one zone of the building is assigned to provide preferred service for another zone of the building.

It is a still further object of the invention to provide an elevator system wherein an elevator car starts from a fioor at which it has stopped after the expiration of a predetermined time to answer a call for service and wherein the time which must elapse before the elevator car starts from a floor at which it has stopped is varied as a function of a predetermined traflic demand.

Other objects of the invention will be apparent from the following discussion taken in conjunction with the accompanying drawing, in which:

Figure l is a view in elevation with parts broken away of an elevator system embodying the invention;

Fig. 2 is a view in elevation with parts broken away of a floor selector suitable for the system of Fig. 1;

Figs. 3 and 4 are schematic views in straight line form showing circuits suitable for the system of Fig. 1;

Figs. 3A and 4A are schematic views showing most of the electromagnetic switches and relays employed in the circuits of Figs. 3 and 4. If Figs. 3 and 4 are placed in horizontal alignment respectively with Figs. 3A and 4A, it will be found that the respective contacts and coils of each pair of aligned figures are substantially in horizontal alignment;

Fig. 5 is a schematic view in straight line form showing modified circuits suitable for the system of Fig. l; and

and coils of the two figures are substantially in horizontal alignment. Inasmuch as the call registering relays for the various floors are somewhat similar, certain of these re- 55 lays have been omitted from Figs. 4A and 5A to conserve space.

Electromagnetic relays and switches employed in the elevator system may have break contacts which are closed when the relays and switches are deenergized and dropped out. Also, the relays and switches may have make contacts which are closed when the switches and relays are energized and picked up. Break contacts are open when the switches and relays are energized and picked up, whereas make contacts are open when the switches and relays are deenergided and dropped out.

In order to distinguish the sets of contacts employed for each relay, each set will be designated by the reference character for the relay followed by the numeral corresponding to the specific set of contacts. For example, the reference character U3 designates the third set of contacts for the up switch U.

In order to facilitate the consideration of the invention, the following apparatus is listed:

V-High-speed relay UUp switch D-Down switch GInductor holding relay ETSIOWdOWI] inductor relay F-Stopping inductor relay M.-Car running relay W -Up-direction preference relay X-Dbwn-direction preference relay H-High car-call relay T-Car-call stopping relay S-Floor-call stopping relay K-High floor-call relay J-Reversing relay PBypass relay HZHigh zone relay L ZLow zone relay SQ-r-Sequence relay 70Non-interference relay 78Call relay FIGURE 1 Fig. 1 shows the mechanical arrangement of various parts of the elevator system. In Fig. l, a cable passes over a sheave 11 and has its ends attached respectively to the elevator car A and to a counterweight 12. The sheave 1-1 is secured to the shaft 13 of a driving motor 14. A conventional spring-applied elcctromagnetically-released elevator brake 15 is associated with the shaft E3 of the motor.

In the operation: of an elevator car, certain contacts are made or broken as the elevator car reaches predetermined positions in its hoistway. Although the elevator car may actuate suitable switches located in the hoistw'ay, it is common practice to provide a floor selector for this purpose. A typical floor selector 16 is illustrated for the car A.

The floor selector 16 has a brush carriage 17 on which suitable brushes are mounted for movement relative to contact segments inv accordance with motion of the eleva tor car. In Fig. 1, two brushes 32 and 42 are illustrated which coact respectively with rows of contact segments b2, etc, and g2, etc. The arrangement of the contact segments will he discussed further in connection with Fig. 2.

The brush carriage 17 may be reciprocated in accordance with movement of the elevator car, but at a much slower rate, by means of a screw 18 which is coupled to the shaft 13'through suitable gearing.

The elevator car may be of the automatic type which is controlled entirely by passengers desiring elevator car service. Alternatively, the elevator car may be of the attendant-operated type. Thus, the elevator car A has a switch CS which is operated by the car attendant to en- 4, gage a contact CS1 when the elevator car is to start. The elevator car also has a number of car-call push buttons 2c to 70. The numeral for each car-call push-button reference character designates the floor with which the push button is associated. Thus, if a passenger desires to be discharged at the seventh floor, the passenger or car attendant would press the push button 7c.

A slowdown inductor relay E and a stopping inductor relay F are employed in conditioning the elevator car A to stop at a floor. When the elevator car is to stop at a floor, the coil for the slowdown inductor relay E is energized. Such energization does not result in pickup of the break contacts E1 and E2 until the elevator car reaches predetermined positions wherein the inductor relay is adjacent a magnetic inductor plate UEP or DEP. One of the inductor plates UEP is provided for each. of the doors at which the elevator car A is to stop during up travel. When the elevator car is a predetermined distance from a floor at which it is to stop, the up-inductor plate UEP for the floor is adjacent the inductor relay E and completes a magnetic circuit for opening the break contacts El. Such opening initiates a slowdown of the elevator car. When once picked up, the contacts may remain open until the inductor relay coil is deenergized, even though the relay passes an inductor plate.

In a similar manner, a down-inductor plate DEF is provided for each floor at which the elevator car is to stop during down travel. When the elevator car approaches a floor at which it is to stop, the inductor plate DEE completes a magnetic circuit for the inductor relay E to open the break contacts E2 and initiate a slowdown of the elevator car A.

In a somewhat similar manner the stopping-inductor relay F cooperates with up inductor plates UFP and downinductor plates DFP to bring the elevator car to a stop at any desired floor. Thus, when the elevator car approaches a floor at which it is to stop when traveling in the up direction, one of the inductor plate UFP completes a magnetic circuit for the inductor relay to open the break contacts Fl. if the elevator car is traveling in 'a down direction, one of the inductor plates DFP cooperates with the inductor relay to open the break contacts F2 a short distance in advance of the floor at which the elevator car is to stop. Such inductor relays are well known in the art.

Calls for elevator car service from passengers located at various floors served by the elevator cars are registered by suitable push buttons located at the various floors. For example, at the second floor, an up push button 2U may be operated to register a call for up elevator car service. A similar push button would be located at each floor from which up elevator car service is desired. Each up push button is identified by the reference character U preceded by a numeral corresponding to the floor at which the push button is located. In an analogous manner, a down push button (identified by the letter D preceded by a numeral corresponding to the floor at which the push button is: located) is located at each hall or door from which down elevator car service is desired. The downcall push button 21) is illustrated in Fig. l for the second floor.

A switch iiB is mounted in the elevator car to be operated when the elevator car is fully loaded or is to pass registered floor calls without stopping. The switch may be a push button to be operated by a car attendant.

Alternatively, the switch may be responsive to the load on the platform of the elevator car. Such switches are well known in the art.

FIGURE 2 Fig. 2 shows in greater detail the arrangement of the contact segments; brushes, and switches employed in the" 7 As the elevator car A moves upwardly, a brush 30 mounted on the brush carriage 17 successively engages contact segments (42 to 127. This brush has a length sufiicient to bridge successive contact segments and is employed in controlling a high car-call relay H. A brush 31 mounted on the brush carriage also engages successively the contact segments to control a car-call stopping relay T during up travel of the elevator car A. The numeral employed in each contact segment reference character designates the floor with which the contact segment is associated.

During up travel of the elevator car A, a brush 32'. on the brush carriage 17 successively engages contact segments b2 to 126 to control a floor-call stopping relay S.

During up travel of the elevator car A. a brush 33 successively engages contact segments c2 to 06 for the purpose of cancelling floor calls for which the elevator car stops.

During up travel of the elevator car, a brush 3-! mount- 1 ed on the brush carriage successively engages contact segments d1 to (Z7 for the purpose of controlling a high floor-call relay K. The brush 34 has a length sufficient to bridge successive contact segments.

During down travel of the elevator car A, a brush 41 mounted on the brush carriage successively engages cOntact segments f7 to f2 for the purpose of cancelling floor calls answered by the elevator car while set for down travel.

During down travel of the elevator car A, a brush 42 mounted on the brush carriage 17 successively engages contact segments g7 to g1 for the purpose of controlling the floor-call stop relay S.

During down travel of the elevator car A, a brush 43 mounted on the brush carriage 17 successively engages contact segments I26 to M for the purpose of controlling the car-call stopping relay T.

During up travel of the elevator car, a brush 36 engages successively control segments Irl to k7 for the purpose of controlling the high zone relay HZ and the low zone relay LZ.

When the elevator car is adjacent the lower terminal floor a cam 38 engages and opens a normally-closed mechanical switch 39 and engages and closes a normallyopen mechanical switch 40.

During up travel of the elevator car A, a cam 49 successively opens normally-closed mechanical switches 52- to 56, which are associated respectively with the second to the sixth floors. The cam 49 has a length sufiicient to bridge the operating members of successive switches. 7

These switches are employed in controlling the energizetion of the high call-car relay H and the car-call stepping relay T.

FIGURE 3 Fig. 3 shows various control circuits for the elevator system. Although various motor drives may be employed for the system, it will be assumed that a drive of the vari'able-voltage-type is employed. In such a drive, the motor 14 is a direct-current motor which has its armature 14A energized from the armature GA of a direct-current generator GB. The direct-current generator is rotated at a constant rate by a suitable motor (not shown). The armatures 14A and GA, together with a generator series field winding GS, are connected by a circuit 22 in series in a loop circuit. The field winding MP for the motor 14 is connected directly to a source of direct current represented by the buses L+ and L.

The release coil for the brake 15 is connected for energization across the buses L+ and L either through make contacts U1 of an up switch or make contacts D2 of. a down switch.

The direction of travel of the elevator car A is determined by the polarization of the generator field winding 6 GF. When the make contacts D1 and D3 of the down switch are closed, the generator field winding is connected through a resistor R1 across the buses L-land'L- for energization with proper polarity for down travel of. the elevator car. if the generator field winding is connected through the resistor R1 and the make contacts U2 and U3 of the up switch across the buses L+ and L-, the polarity of energization of the field winding is suitable for up travel of the elevator car. Maximum speed of the elevator car is obtained by shunting the resister R1 through make contacts V1 of a speed relay.

For up travel the speed relay V is energized through break contacts E1 of the slowdown inductor relay, normally-closed contacts of an upper cam-operated limit switch VTU and make contacts U4 of the up switch. If the elevator car is to slow down adjacent a floor at which it is to stop, the break contacts E1 of the slowdown inductor relay open to deenergize the speed relay V. Also, if the car reaches its upper limit of travel a cam opens the limit switch VTU to deenergize the speed relay.

For down travel, the speed relay V is energized through break contacts E2 of the slowdown inductor relay, normally-closed contacts of a cam-operated lower limit switch VTD and make contacts D4 of the down switch.

If the elevator car is to slow down as it approaches a floor at which it is to stop, the break contacts E2 open to deenergize the speed relay. If the car nears its lower limit of travel, a cam opens the lower limit switch VTD to deenergize the speed relay.

By manipulation of his car switch CS, a car attendant controls the initial cnergization of a car running relay M and either the up switch U or the down switch D. The relays and switches can be energized only if certain safety devices 23 are in their safe conditions. These safety devices may include contacts which are closed only if the various hoistway doors and the car doors are closed.

it wil be assumedthat the elevator car stops automatically in response to registered car calls and registered floor or hall calls. I f the elevator car is conditioned for up travel, make contacts W1 of the tip-direction preference relay are closed, and the following circuit is established by operation of. the car switch:

L+, cs, cs1, W1, F1, STU, U, M, 23, L-

This conditions the elevator car for up travel. It will be noted that energization of the up switch U results in closure of the make contacts US to establish a holding circuit around the car switch and the contacts W1. Consequently, stopping of the elevator car is independent of the condition of the car switch.

L+, CS, CS1, X1, F2, STD, D, M, 23, L-

Operation of the down switch D closes make contacts D5 to complete a holding circuit around the car switch and the contacts X1.

If the down-traveling elevator car approaches a floor at which it i to stop, the stopping inductor relay finally opens its break contacts F2 to deenergize the down switch D and the car running relay M. As the elevator car nears its lower limit of travel, the normally-closed limit switch STD is opened by a cam to assure deenergization of the down switch D and the car running relay.

If the elevator ear is to be operated without a car attendant, the switch 61 is closed to establish two shunt paths around the on switch CS. The first shunt path includes, in series, break contacts 784, of a call relay and break contacts 70-1 of a non-interference relay 70. The former contacts are closed if a call for sen ice is registered. The contacts 70-1 are closed after the elevator car has stopped at a fioor long enough for passengers to enter or leave the elevator car.

The second shunt path around the car switch includes normally-open contacts of the mechanical switch 40 which are closed when the elevator car is adjacent the lower terminal floor, make contacts P of the by-pass relay P, and break contacts MS of the car running relay M.

When the switch 61 is closed a switch 61A may be opened to disconnect the car switch.

The non-interference relay 70 has a delay in drop out sufficient to permit a reasonable time for loading and unloading the elevator car. The delay may be provided in any suitable manner, as by a resistor R2 connected across the relay coil. The relay is energized through make contacts M6 of the car running relay M.

The coils of the inductor relays E and F, and the coil of an inductor holding relay G are energized through make contacts M1 of the car running relay, and any one of three sets of make contacts. Thus, if the elevator car i to stop in response to a car call, the make contacts T1 close to energize the coils. If the elevator car is to reverse at an intermediate floor, the make contact 11 of a reversing relay close to energize the coils. If the elevator car is to stop in response to a registered floor or hall call, the make contacts S1 of the floor call stopping relay close to energize the coils. When the inductor holding relay G is once energized, it closes its make contacts G1 to establish a holding circuit until the contacts M1 of the car running relay open. The energizetion of the stopping inductor relay F also is controlled by break contacts V2 of the speed relay.

The up-direction preference relay W can be energized only it the elevator car is not traveling down (break contacts D6 are closed), the elevator car is not conditioned for down travel (break contacts X2 are closed), the reversing relay is not energized (break contacts J2 are closed), and the elevator car is not adjacent its upper limit of travel (normally-closed cam-operated switch 301' is closed).

The tip-direction preference relay W, when once energized, is deenergized in either of two ways. As the elevator car reaches its upper limit of travel, a cam opens the normally-closed limit switch 150T to deenergize the rip-direction preference relay. In addition, if the elevator car is to reverse at an intermediate floor, the break contacts J2 of the reversing relay open. Consequently,

as the elevator car comes to a stop at the intermediate floor, the make contacts M2 of the car running relay open to complete the deenergization of the tip-direction preference relay.

The down-direction preference relay X can be encrgiz'e'd only it the elevator car is not traveling up (break c'ontac'ts U6 are closed), the tip-direction preference relay W is not energized (break contacts W2 are closed), and the elevator car is not adjacent its normal lower limit of travel at the first floor (limit switch 388 is closed). When once energized, the down-direction preference relay normally can be deenergized only as it nears its normal lower limit of travel. Under such circumstances, a cam opens the normally-closed limit switch 303 to deenergize the down-direction preference relay.

The right-hand column of circuits in Fig. 3 shows the circuits for controlling the up call-storing relays and the fioor-call stopping relay S.

When the second floor up call button EU is pressed, the up can-storing relay ZUR is connected across the buses L+ and" L-.' As a result of its energization', the

relay closes its make contacts 2UR1 to establish a holding circuit around the push button 2U. It will be noted that the contact segment [72 which controls the stopping of up-traveling elevator car at the second floor is connected to the bus L+ through the make contacts 2UR1.

in the elevator car A is traveling up, make contacts W3 of the up-direction preference relay are closed, and when the brush 32 reaches the contacts segment b2, the following energizing circuit is completed:

L+, 2on1, b2, 32, W3, 62, NS, s, L

The floor-call stopping relay now is energized to initiate the stopping of the elevator car A at the second floor. The switch NS may be employed to prevent the elevator car from responding to fioor calls it the elevator car is fully loaded. The switch is normally closed and opens in response to full loading of the car. Such switches are well known.

As the elevator car comes to a complete stop the brush 32 may pass slightly beyond the contact segment b2. If the switch 62 is open, the last-named circuit is inefiective for initiating a stopping operation.

If a stopping operation of the elevator car A at the second floor is initiated, the brush 33 engaged the contact segments 02 and completes the following circuit:

L+, ZURZ, ZURN, c2, 33, W4, M3, L

The resulting energization of the cancelling coil ZURN cancels the call at the second floor. The coil for the relay 2UR and the coil ZURN may be wound 'in opposition so that the energization of the cancelling coil ZURN results in resetting of the relay ZUR. It will be understood that a similar up call-storing relay and a similar cancelling coil would be associated in the same manner with each. of the up call push buttons.

it a prospective passenger at the second floor presses the down-call push button 213, the down callstoring relay ZDR is connected for energization across the buses 1+ and L-. This relay closes its make contacts 2DR1 to establish a holding circuit around the push button. The contact segment 32 now is connected through the contacts 2DR1 to the bus L+.

if the elevator nears the second floor while traveling down, the brush 42 engages the Contact segment g2 to complete the following circuit:

L+, 2DR1, g2, 42, X3, P1, NS, S, L

The energization of the floor-call stopping relay prepares the elevator car to stop at the second floor.

As the elevator car comes to a complete stop, the brush 42 may pass slightly beyond the contact segment g2. if the contacts Pl and the switch 63 are open, the last-named circuit is ineffective for initiating a stopping operation.

Following the initiation of the stoppingoperation at the second floor, the elevator car A has its brush 41 engage the ccntact segment f2 to compl te the following circuit:

L+. ZDRl, ZDRN, f2, 41, X4, M3, L-

The resulting energization of the cancelling coil ZDRN resets the down call-storing relay 2BR in the same manner discussed for the relay ZUR.

Each of the down floor or hall call push buttons has a similar down call-storing relay and a similar cancelling coil associated therewith in the same manner.

The elevator car answers a down floor call at the upper terminal floor while traveling up. Consequently, the down call-storing relay 7BR and the cancelling coil 7DRN are associated with the contact segments b7 and c7.

Inasmuch as the elevator car answers an up floor call at the lower terminal floor while traveling down, the up call-storing relay lUR and the cancelling coil I-URN are associated with the Contact segments g1 and f1.

FIGURE 4 The upper left-hand part of Fig. 4 shows circuits for controlling the high car-call relay H and the car-call stopping relay T.

Each of the car-call push buttons 20 to 7c normally is open. its pressed condition until the elevator car reverses its direction of travel. Thus, each of the buttons may be constructed of magnetic material, and when pressed, may be maintained in its pressed condition by means of a holding coil 20c to 700. The prefixes 2 to 7 of these reference characters designate the respective floors with which the components are associated. The holding coils are connected in series across the buses L+ and L-, either through make contacts W6 or the make contacts X6 of the preference relays. These contacts both are momentarily open to reset the car-call push buttons when the elevator car reverses its direction of travel.

Each of the car-call push buttons for the intermediate fioors when operated connects two contact segments to the bus L+. Thus, the car-call push button 20, when pressed, connects the contact segments a2 and 122 to the bus L+. The elevator car does not have passengers desiring the seventh floor during down travel, and consequently only one contact segment a''/' need by connected through the car-call push button 7c to the bus L+.

If the elevator car A is traveling up, and ii a car call is registered for the fourth floor, the brush 31 engages the contact segment a4 a predetermined distance in advance of the fourth floor to energize the car-call stopping relay T through the circuit:

L+, 40,114, 31, W5, T, M4, L

The car-call stopping relay then initiates a stopping operation of the elevator car. The parts may be so related that the brush 31 leaves the contact segment shortly before the elevator car comes to a full stop.

If the elevator car A were traveling down with a pa"- senger to be discharged at the fourth floor, the following circuit would be completed as the elevator cars nears the fourth floor:

L+,'4c, 114, 43, X5, T, M4, L-

Consequently, the car-call stopping relay T again would be energized to initiate the stopping operation of the elevator car A at the fourth floor. The parts may be so related that the brush 43 leaves the contact segment I14 shortly before the elevator car comes to a full stop.

Inasmuch as the elevator car when traveling down always stops at the lower terminal floor, the contact segment hl is directly connected to the bus L+.

The high car-call relay H when energized indicates the presence of a registered car call for a floor above the position of the elevator car. The mechanical switches 52 to 56 are employed in controlling the energization of this high car-call relay. It will be noted that one of the mechanical switches is connected across each successive pair of contact segments. The mechanical switches connected to the contact segments corresponding to the position of the elevator car or to the floor directly below the elevator car are opened by the cam 49 to prevent energization of the high car-call relay H through carcall push buttons for the lower floors and to prevent energization of the car-call stopping relay except through However, when pressed, each button is held in the push button for the floor which the elevator car is nearing. However, if any car-call push button is pressed for a floor above the position of the elevator car, a cit cuit is completed for the high car-call relay H through the intermediate mechanical switches. Thus, with the elevator car at the third floor, as shown in Fig. 5, if a car call is registered for the sixth floor, the following circuit would be completed:

L+, 6c, 55, 54, a4, 30, H, L-

The car-call circuits are standard in the art.

The reversing relay J is energized in order to reverse the direction of the elevator car at an intermediate floor. For the specific system herein shown, the reversing relay I is effective only during up travel of the elevator car. For the relay to be energized, no car calls must be registered for a floor above the position of the elevator car (break contacts H1 are closed), the car must be traveling up (make contacts W7 are closed) the car must be running (make contacts M7 closed), and no floor call must be registered for a fioor above the position of the elevator car (make contacts K1 are closed).

The high floor-call relay K, together with the call relay 78 are controlled in part from a call above indicator circuit 59. This circuit 50 includes break contacts for all of the call-storing relays connected in series. The contacts are so arranged that those associated with callstoring relays requiring up travel of the elevator car are located above the point of contact of the brush 34 with the contact segments :11 to (16. The order in which the contacts are connected and the points of connection to the circuit 50 of the contact segments :11 to d7 may be ascertained by inspection of Fig. 5. Such call above indicator circuits are well known in the art.

The high floor-call relay K can be energized only if no floor call for a floor above the position of the elevator car is registered (all break contacts of the call-storing relays above the position of the brush 34 are closed), and the elevator car A is traveling up (make contacts W8 are closed).

During periods of heavy demand for elevator service in the down direction the elevator car may be conditioned to ignore up floor calls at some or all floors. To this end break contacts 2UR2 and 3UR2 of the up call-storing relays for the second and third floors in the call above indicator circuit are shunted by make contacts P6 and P7 of the by-pass relay P, as clearly shown in Fig. 4.

The call above indicator circuit 56 together with break contacts H2 of the high car call relay H control the energization of the call relay 78. As clearly shown in Fig. 4 if a call is registered from any floor of the building one of the sets of break contacts in the call above indicator circuit 50 will be opened to prevent energization of the call relay 78. If a call is registered by a passenger in the elevator car the break contact H2 of the high car call relay H will be opened to prevent energization of the call relay 78.

The circuits located in the right-hand column of Fig 4 control the energization of the by-pass relay 1', the high zone and low zone relays HZ and LZ and the sequence relay SQ.

Assuming that the switch 81 is closed, the by-pass relay P can be energized initially only if the elevator car is in the high zone (make contacts H21 are closed and break contacts LZI are closed), the elevator car is set for down travel (make contacts X7 are closed) and the switch PB is closed.

The switch PB closes its contacts when the elevator car is loaded to capacity. If an attendant is provided in the elevator car the switch PB may be a manually-operated switch which is operated at the proper time by the car attendant. However, it will be assumed for present purposes that the switch PB is an automatic load-responsive switch. Such load-weighing switches for elevator cars are well known in the art.

When'the by-pa's's relay P picks up, it closes its holding contacts P3. Thereafter the relay can be deenergized only if the break contacts SQI of the sequence relay are open, the break contacts LZ'l of the low zone relay are open and the make contacts W9 of the up direction preference relay 'W are open.

The high zone and low zone relays are associated with a row of contact segments k1 to k7 located on the floor selector as previously discussed with reference to Fig. 2. Although the distribution of floors between the high and low zones may be selected to satisfy the requirements of each'builcling, it will be assumed for the present that the high-zone includes the fifth, sixth and seventh floor whereas the low zone includes the first, second, third and fourth floors.

By reference to Fig. 4 it will be noted that one terminal of the high zone relay HZ is connected to the contact segments k5, 1:6 and k7 forthe high zone floors. The remaining terminal of the relay is connected to the bus L-.

In an analogous manner one terminal of the low zone relay LZ is connected to the contact segments kl to k4 for the low zone floors, whereas the remaining terminal is connected to the bus L.

The'brush 36 is connected to the bus L+. This brush 36 has a length sufiicient to bridge successive contact segments with the exception of the contact segments M and k5. To'prevent simultaneous energization of the high zone and low zone relays, the contact segments I24 and :25 may be spaced apart by a distance slightly greater than the corresponding dimension of the brush 36.

Byinspection ofFig. 4 it will be noted that as long as the elevator car is in the low zone of floors the low zone relay LZ is energized. As long as the elevator car is in the high zone of doors the high zone relay HZ is energized.

The sequence relay SQ can be energized initially only if the make contacts P4 of the bypass relay P are closed audit the make contacts W19 of the up direction preference'relay W are closed. When it picks up, the sequence relay closes its make contacts SQZ to establish a holding circuit aroundthe contacts W10.

Operation It is believed that'an understanding of the invention will be facilitated by a brief review of a typical operation of the elevator system. It will be assumed initially that the elevator car is located at the lower terminal floor and that a down floor call is registered for the sixth floor. By reference to Fig. 3, it will be noted that the registration of the floor call is effected by pressing .the push button 61) which energizes the down call-storing relay 6BR. The down call-storing relay closes its make contact 6DR1 to establish a holding circuit around the push button 6D and to connect the contact segment 36 to the bus L+. As shown in Fig. 4, the down call-storing relay 6DR also opens its break contacts 6DR2 to prevent energization of the high floor-call relay K and of the call relay 78.

Since the elevator car is at the lower terminal floor, the limit switch 303 (Fig. 3) is open, and the down-direction preference relay is deenergized. Also, the upper limit switch 30T is closed, and the tip-direction preference relay W is energized.

'The'elevator car attendant now operates the car switch CS and closes the doors of his car to complete the following'circuit:

L+, CS, CS1, W1, F1, STU, U, M, 23, L

If the 'elevator car is operating without an attendant the switch 61 is closed. Since a call is registered, the call relay '78 is deenergized and the break contacts 78-1 are closed. If the-elevator car'hasbeen at the lower terminal fioor'for a'sufiicient timeto'permit loading or unloading, the non-interference relay has timed out and the break contacts 70-4 are closed to complete the following cirucit:

L+, 78 1, 61, 70-LVV1, F1, STU, U, M, 23, L

Energization of the car running relay M has no immediate effect on the operation of the system except that closure of contacts M6 picks up the non-interference relay 70 which opens its break contacts 70-1.

Up switch U closes its make contacts U1 to release the brake l5. Closure of make contacts U2 and U3 connects the generator field winding GF with proper polarity for up travel of the elevator car, and the elevator car starts in an up direction. Make contacts U4 close to energize at the speed relay V through the limit switch V.TU and the contacts E1 of the slowdown inductor relay. The speed relay thereupon closes its make contacts V1 to shunt the resistor R1 and permit ,full speed operation of the elevator car. Also, the speed .relay opens its break contacts V2 to prevent energization .of the Stopping .inductor relay F.

Closure of the make contacts U5 establishes a holding circuit around the car switch and the contacts W1. If the elevator car is on car switch control, the car switch now may be released. If the elevator car is operating without a car attendant, the contacts U5 close before the contacts 70-1 open to maintain energization of the relays U and M. Break contacts U6 open to prevent energization of the down-direction preference relay X.

As the elevator car leaves the lower terminal floor, mechanical switches VTD (Fig. 3), STD and 30B close and switch 40 opens without affecting the operation of the system. In addition, the mechanical switch 39 closes to energize the call-storing relay iUR for the purpose of registering a parking call for the lower terminal floor. The relay lUR closes its self-holding contacts IURLLand opens its break contacts iURZ (Fig. 4).

Turning now to Fig. 4, it will be noted that as the elevator car A nears the sixth fioor, the brush 34 engages the contact segment d6 which is connected to the call above indicator circuit 5% above the open contacts 6DR2. Consequently, the high floor-call relay K is energized through the circuit:

L+, 7DR2, 6UR2, d6, 34, W8, K, L-

As a result of its energization, the high floor-call relay K closes its make contacts K1 to complete an energizing circuit for the reversing relay 1. It is assumed that no car call is'registered for a floor above the position of the elevator car A and that'the break contacts H1 are closed.

As a result of its energization, the reversing-relay J closes its make contacts 33 to establish a holding circuit around the contacts M7 and K1. In addition, the reversing relay closes its make contacts 31 (Fig. 3) to energize through the contacts .M1, the coils of the inductor holding relay G and the inductor relay-E.

Upon energization,.the inductor holding relay G closes its make contact G1 to establish a holding circuit around the contacts 11.

Referring to Fig. l, the coil of the slowdown inductor relay'E for the elevator car A now is energized. When the inductor relay reaches the up-inductor plate UEP for the sixth floor, the magnetic circuit is completed which results in opening of the break contacts El.

Theopening of the break contacts E1 deenergizcs the speed relay 'V (Fig. 3). Consequently, the make contacts V1 open to introduce the resistor R1 in series with the generator field winding GF. This slows the elevator car A to a landing speed. In addition, break contacts V2 opento energize the coil of the stopping-inductor relay F through the contacts G1 and M1.

Upon continued movement of "the elevator car towards the sixth floor, the stopping-inductor relay P (-Fig. 1) reaches the up-inductor plate UFP' for the sixth'floor-to complete 'a'magnetic circuit-which results in opening of 13 the break contacts F1. The opening of these contacts deenergizes the up switch U (Fig. 3) and the car running relay M.

As a result of its deenergization, the up switch U opens its contacts U1 to deenergize the coil of the brake 15 and to permit the spring-applied brake to move into braking condition. in addition, the contacts U2 and U3 open to deenergize the generator field winding. The elevator car now stops at the sixth floor.

The up switch U opens its make contacts U4 and U5, and closes its break contacts U6. Such contact operations have no immediate effect on the system. The deenergization of the car running relay M results in opening of the make'contacts M1 to deenergize the coils of the inductor holding relay G and of the inductor relays E and F. Also, make contacts M2 open. Since the reversing relay has already opened the break contacts 12, it follows that the up-direction preference relay W now is deenergized. Opening of the make contacts M4 (Fig. 4)

has no immediate effect on the operation of the system.

Closing of the break contacts M5 (Fig. 3) and the opening of contacts M7 (Fig. 4) have no immediate effect on the system. However, opening of the make contacts M6 deenergizes the non-interference relay which now starts to time out.

The car running relay also closes its break contacts M3 to complete in part the call-cancelling circuit to floor relay 6DR.

The deenergization of the rip-direction preference relay results in opening of the make contacts W1, W3, W4, W5, W6, W9 and W10 without immediate eflect on the operation of the system. However, the closing of the break contacts W2 (Fig. 3) completes an energizing circuit for the down-direction preference relay X through the lower limit switch 30B and the recently-closed break contacts 11 U6 of the up switch. Opening of the contacts W7 and W8 deenergizes the relays I and K. The relay I opens its contacts 11, 12 (Fig. 3) and B (Fig. 4), and the relay K opens its contacts K1 without immediately affecting the operation of the system.

The down-direction preference relay X closes its make contacts X1, X3, X5 and X6 to prepare the elevator car for operation in the down direction. Opening of the break contacts X2 (Fig. 3) prevents energization of the tip-direction preference relay W. Closure of the make contacts X4 (Fig. 4) completes through the recently closed contacts M3 of the car running relay, the following circuit:

L+, 6DR1, 6DRN, f6, 41, X4, M3, L

The cancelling of the call causes the relay 6BR to drop to its deenergized condition wherein the self-holding contacts 6DR1 are open. The break contacts 6DR2 (Fig. 4) close without immediately aflfecting the operation of the system. As a result of the continued energization of the cancelling coil '6DRN, the down floor call for the sixth floor is held cancelled until the car leaves the floor on its down trip.

It will be assumed next that at the sixth floor a sutficient number of passengers enter the elevator car to operate the switch PB indicating that the elevator car is loaded to capacity. When the elevator car enters the high zone, the low zone relay LZ (Fig. 4) was deenergized as the brush 36 left the contact segment k and the high relay HZ was energized as the brush 36 engaged the contact segment k5. Consequently, while the elevator car'remains at the sixth floor the make contacts HZ]. are closed and the break contacts 111 are closed. In addition, since the make contacts X7 are closed, the bypass relay P is energized through the circuit:

L., PB, HZI, X7, L21 and SQ1 in parallel, 31, l, L

The bypass relay P closes its make contact P3 to establish a holding circuit around the switch PB and the contacts 14 HZl and X7. Break contacts P1 (Fig. 3 open) and make contacts P2 (Fig. 4) and P4 closed without immediately affecting the operation of the system. If make contacts P6 and P7 are employed, these close without immediate eitect on system operation.

It will be recalled that as the elevator car left the first floor the switch 39 (Fig. 3) closed to energize the call storing relay lUR for the purpose of registering a call for the first floor. Consequently, the break contacts UR2 (Fig. 4) are open and the call relay 78 is deenergized. This means that the break contacts 781 (Fig. 3) are closed.

Upon expiration of the time required for the noninterference relay 70 to drop out, this relay closes its break contacts 70-1 to complete the following circuit:

L+, 734., 61, 7ti1, X1, P2, STD, D, M, 23, L

The down switch D and the car running relay M now are energized. (If the elevator car is on attendant operation, the car switch CS would be operated to energize the relays D and M.)

The down switch D closes its make contacts D2 to energize the elevator brake 15 for the purpose of releasing the brake. In addition, contacts D1 and D3 close to energize the field winding GF with proper polarity for down travel of the elevator car. Make contacts D4 close to complete with the contacts E2 and the limit switch VTD an energizing circuit for the high speed relay V. This relay closes its make contacts V1 to shunt the resistor R1 and opens its break contacts V2 to prevent energization therethrough of the stopping inductor relay F. Make contacts D5 close to establish a holding circuit around the contacts 784, 701 and X1 or around the car switch CS and X1. Opening of the break contacts D6 has no immediate effect on the operation of the system. The elevator car now is in condition for full speed operation in the clown direction and leaves the sixth fioor.

The running relay M closes its make contacts M6 to reenergize the non-interference relay 70. This relay opens its break contacts 70-1 without immediate effect on the operation of the system.

In addition, the car-running relay M closes its make contacts M1, M2 opens its break contacts M3, M5 and M7 and closes its make contacts M4 (Fig. 4) without immediately affecting the operation of the system.

At this point it will be assumed that a down floor call is registered by a prospective passenger at the third floor. This passenger operates the push button 3D (Fig. 3) to complete an energizing circuit for the down call storing relay 3BR. The relay closes its self-holding contacts 3DR1 and opens its break contacts 3DR2 (Fig. 4) without immediately affecting the operation of the system.

As the elevator car proceeds in the down direction, the brush 42 engages the contact segment g3. However, since the contacts P1 of the bypass relay are now open the floor call stopping relay S cannot be energized through the contact segment g3 and the elevator car passes the third fioor without stopping.

As the elevator car nears the first floor, the brush 43 engages the contact segments 111 to complete with the contacts X5 and M4 an energizing circuit for the car call stopping relay T. This relay closes its make contacts T1 (Fig. 3) to complete with the contacts M1 an energizing circuit for the inductor holding relay G and the slowdown inductor relay E. Upon continued motion of the elevator car toward the first floor, the inductor plate DEP for the first floor completes a magnetic circuit for the inductor relay E which results in opening of the contacts E2 to deenergize the high speed relay V. This relay opens the make contacts V1 to introduce the resistor R1 in the energizing circuit for the generator field winding GF and the elevator car now slows to a landing speed. In addition, break contacts V2 close to complete "15 with thecontacts G1 and M1, an energizing circuit "for the stopping inductor relay F.

Further movement of the elevator car toward the first floor brings the inductor plate FDP (Fig. 1) adjacent the stopping inductor relay F to complete a magnetic circu'it which results in opening of the contacts F2. Such opening results in deenergization of the down switch "D (Fig. 3) and the car running relay M.

The down switch opens its make contacts D2 to .deenergize the elevator brake Y15 and permit reapplication of the brake. In addition, make contacts 'Di and'DS open to deenergize the generator field winding GF and the elevatorcar now stops accurately at the firstfioor. Opening of the make contacts D4 and D5 and closure of .the break contacts D6 have no eifect on the immediate operation of the system.

When deenergized, the car running relay M opens its make contacts M1 to deenergize the relays G, E and F. The relay G opens its holding contacts G1. The relay also opens its contacts -M2 without immediately affecting the operation of the system. Closure of break contacts M3 and openingof make contacts M4 and M7 (Fig. 4) have no .eifecton the immediate operationof the system. Closure of the break contacts M5 (Fig.3) completes with the make contacts P5 and the mechanical switch 40 which is closed when the car isat the first floor a shunt around the break contacts 70-4 of the non-interference relay 70. This permits prompt starting of the elevator car from the first floor. The contacts MS may close with a small time delay if a small .unloading time is desired.

As the elevator car reaches the first floor the limit switches STD and 31B open, and the doors open automatically in a conventional manner or are opened by the car attendant or by a car passenger in a conventional manner. Theopening of theswiteh STD has no efiect on the operation of .the system at this time. However, opening of the switch 30B results in deenergization of the down-direction preference relay X. The'down direction preference relay consequently opens its make contacts X1, X3, X4, X5 (Fig. 4), X6 and X7 without immediately affecting the operation of the system. However, closure of the break contacts X2 (Fig. 3) completes with the contacts D6, 12 and the switch 30T an energizing circuit for the up direction preference relay W.

The up direction preference relay opens its break contacts W2, closesits make contacts W3, W4, W5 '(Fig. 4), W6, W7, W8 and W9 without immediately afiecting the operation of "the system. Closureof the make contacts W16 completes .withthe contacts P4 an energizing circuit L+, 78-Z, 61, 40, P5,,M5, WLFL STU, U, M, '23, L-

It should be noted that this circuit may be completed before the non-interference relay 7tl'has timedout. This is desirable for the reason that the elevator car is assigned to provide preferred servicefor the low zone of floors and it is preferable that the elevator car leave the first floor without accepting passengers from the first floor. If desired, the entry of passengers into the car may be further discouraged by suitable information-conveying means operated by the bypassrelay P. For example, when the bypass relay'P operates, a sign (not shown) at the first floor may 'beilluminated'bearing a legend that passengers shonl'dnot entcr the elevator car.

inasmuch as the. up switchU andthe car running relay M are now energized, the elevator car starts in the up lnasrnuchas the contacts Y direction by a sequence which will be understood (from theforegoing discussion. As the elevator car leaves the first floor the mechanical switches STD and 30B reclose without affecting the immediate operationzof the system.

It will be assumed that as the elevator carleaves the first floor adown call at the sixth ,floor isreg-istered. The sequence for registering a call previously has been .discussed. i

It will be understood that the discharge of passengers at the first floor resulted in opening of theswitch PB. Such opening has no immediate efiect on the operation of the system.

-As the elevator car nears the third floor, the brush 3.4 (Fig. 4) engages the contact segments 13 to complete the following circuit:

L{-, P2, 4DR2, 3UR2 and P7 in parallel, d3, 34, W8, K, 'L

It should be noted that the high floor-call relay is reenergized despite the fact that the break contactsfiDR-Z are open because of the call registered ,at the ,sixth floor. The make contacts K1 are now closed to complete 'With the contacts M7, H1 and W7 an energizing circuit for the reversing relay J. The reversing relay initiates the stopping and reversing of the elevator car at the third floor by .a sequence which will be understood from the previous discussion of the stopping and reversing of the elevator car at the sixth floor.

As the elevator car reverses at the third 'fioor, the make contacts W? of the tip-direction preference relay W open. Since the low zone relay contacts LZl and the sequence relay contacts SQl are both open, the bypass relay P is now deenergized. Consequently the bypass relay closes the brealccontacts Pl (Fig. 3) to permit the elevator car to answer down floor calls during its return to the first floor. Opening of the make contacts 'PZfiBd'PS (Pig. 4) has no immediate eliect on the operation of;-the system. Opening of the make contacts P4 deenergizes the sequence relay SQ which opens its snake contacts SQZ and closes its break contacts SQi without. immediately affecting the operation of the system. Since the bypass reiay P is now deenergized, the elevator caron :its next trip from the first floor may enterthe high zone and provide similar service for allof. the floors.

Let it be assumed next that when-the elevator car started from the first floor to-answer the down;floor.call at the third floor, a passenger succeeded in entering the elevator car at the first floor and in registering a car call for the sixth floor. Such a call is registered by operation ofthe button 6c which isheld in its operatedcondition by the holding coil 6cc, and energize therelay Hthrough the circuit:

As the elevator car'nears the third'fioor, thebr-ush 34 again engages the contact segment d3 to-energize-the high fioor-call relay K. However, closure of the make contacts Kl does not result inenergization of the reversing relay I for the reason that the break contacts-H1 ofthe high car call relay H are now open. As the elevator car in its upward motion nears the sixth-floor, the brush-30 leaves the contact segment a6 to deenergize the high car call relay H. This relay closes its break contacts'Hl. in addition, the brush 34- engages the contact'segment d6 to complete with the contacts 7DR2,'6UR2 and W8-an energizing circuit for the high floor-call relayK. 'Since the contacts Hi, W7, M7 and K1 are now closed, the reversing relay I is'energized to stop and reverse the elevator car at the sixth floor by a sequence which will be understood from the preceding discussion.

During its downward movement from the sixth floor the elevator car cannot answer down floor calls ,for the reason that the bypass relay P is energized and the contacts Pl (Fig. 3) are open. Consequently, even though 17 a down floor call were registered at the fifth floor, the elevator car would not stop in response to such a call.

As the elevator car enters the low zone, the brush 36 leaves the contact segment k to deenergize the high zone relay HZ and engages the contact segment k4 to energize the low zone relay LZ. The dropout of the high zone relay HZ has no immediate effect on the operation of the system, however, the pickup of the low zone relay LZ results in opening of the break contacts 111. Inasmuch as the contacts SQ and W9 are also open the bypass relay P now is deenergized and closes its break contacts P1 (Fig. 3) to permit the elevator car to accept down floor calls in the low zone during its return to the first floor. I

In this way it will be appreciated that in the absence of a call for elevator service the elevator car remains parked at the first floor. As calls for service are received the elevator car leaves the first floor to provide similar service for the floors of the building. In the preferred embodiment of the invention the up-traveling elevator car reverses at the highest floor for which a down floor call or a car call is registered provided no up floor call is registered for such fioor or a higher floor.

However, if the elevator car is fully loaded while set for down travel in the high zone of floors the elevator car provides express service to the first fioor and thereafter is assigned on its next up trip to reverse at the highest floor in the low zone for which a down floor call is registered even though a floor call for a floor in the high zone is registered. If while so assigned a car call is registered for a floor in the high zone the elevator car answers such car call and thereafter, if no other car call is registered for a high zone floor, expresses to the highest floor in the low zone for which a down floor call is registered. When the elevator car is assigned to provide preferred service for the low zone of floors the time required for the elevator car to remain at the first floor for the purpose of loading passengers is materially reduced.

FIGURE 5 Fig. 5 illustrates a modified construction of the elevator system. In Fig. 5 circuits are illustrated for the floor-call stopping relay S, the high floor-call relay KA, the sequence relay SQA and the bypass relays 3? to GP.

The circuits which control the floor-call stopping relays S in Fig. 5 are largely similar to those disclosed in Fig. 3. The only differences between the circuits controlling the floor-call stopping relay S in Fig. 5 and those controlling the same relay in Fig. 3 are as follows:

It will be noted that the break contacts P1 of Fig. 3 are replaced by a switch EPA in Fig. 5. The switch BPA has normally closed contacts which are open when the elevator car is fully loaded. The switch SPA may be manually operated but in the preferred embodiment the switch is automatically responsive to the load in the elevator car.

In Fig. 3 th contact segment go is connected to the bus L+ directly through the contacts oDRll. In Fig. 5 the connection is effected not only through the contact 6DR1 but through three sets of break contacts 3P1, 4P1 and SP1. If the elevator car during a down trip is fully loaded at the sixth, fifth or fourth floors, one of the sets of contacts 5P1, 4P1, or SP1 is opened to prevent the elevator car from answering a down floor call at the sixth floor on its next trip. For similar purposes'the contact segment g5 in Fig. 5 is connected to the bus L+ not only through the contacts SDRI but through the contacts 4P2 and 3P2. The contact segment g4 is connected to the bus L+ through the make contacts 4DR1 and the break contacts SP3. The contact segments g3 and g2 for the embodiment of Fig. 5 are connected to the bus L+ in the same manner as in Fig. 3 (circuits for the second floor are not illustrated in Fig. 5).

The high-floor call relay KA is connected between the bus L and a brush 84 through make contacts W11 of the up direction preference relay W. The brush 84 is associated with a row of contact segments ml to m7 which are mounted on the floor selector of Fig. 1. It will be understood that as the elevator car proceeds from the first to the seventh floors, the brush 84 successively engages the contact segments ml to m7. The contact segments m1 is connected to the bus L+ through a circuit 50A which has in series break contacts 2DR3 to 7DR3 of the down-call storing relays ZDR to 7DR arranged in the order of the floors as clearly illustrated in Fig. 5. The contact segments m2 are connected to the circuit 50A between the break contacts 2DR3 associated with the same floor and the break contacts 3DR3 associated with the next higher floor. The contact segments m3 to m6 similarly are associated with the circuit 50A, the connections being clearly shown in Fig. 5. The contact segment m7 is connected to the bus L+.

In addition the contact segments m3 to m6 are connected to the bus L-]- respectively through make contacts of the bypass relays 3P to 6P.

The sequence relay SQA is connected between the bus L and a contact segment 212 which with a brush 85 is mounted on the floor select-0r of Fig. l. The brush 85 is positioned to engage the contact segment n2 when the elevator car is adjacent the second floor. In addition, initial energization of the relay requires closure of make contacts W12 of the up-direction preference relay W and closure of any make contacts of the bypass relays 3P to 6P. When once energized, the relay SQA closes holding contacts SQAl which extends around the contact segment n2, the brush 85 and the contacts W12.

, For the bypass relays 3P to GP to be energized either the break contact SQA2 of the sequence relay must be closed or normally closed contacts of a mechanical switch 86 must be closed. The mechanical switch is associated with a cam 87 which opens the switch 86 when the eleva-tor car is adjacent the first floor.

The bypass relays 3P to 6P are associated with a row of contact segments t4 to t7 and a brush 88 which are disposed on the floor selector of Fig. 1. The brush 88 successively engages the contacts t7 to t4 as the elevator car proceeds from the seventh floor to the fourth floor. When energized each of the bypass relays operates make contacts to establish a holding circuit extending from the associated contact segment to the bus L+.

The brush 88 is connected to the bus L+ through make contacts X7 of the down-direction preference relay X and a switch 89. This switch 89 is momentarily closed each time the switch EPA is operated. For the purpose of illustrating such operation, it will be assumed that the switch 89 has a first contact 89A mounted on a leaf spring 89B which has one end fixed and which has its opposite biased against a stop 89C. A cooperating contact 89D is normally spaced from the movable contact 89A. The free end of the spring 891) is positioned adjacent a spring element 89E which is reciprocated by the operating member of the switch EPA. The spring element 89E has a protuberance 89F.

When the operating member of the switch EPA is operated the spring element 89B is lowered as viewed in Fig. 5 to close the contacts 89A and 89D. Upon continued motion of the operating member of the switch EPA the protuberance 89F passes over the end of the leaf spring 89B and permits the return of the leaf spring into engagement with its stop 89C. Consequently, the switch 89 is closed momentarily for each operation of the switch BPA.

Operation of embodiment illustrated in Fig. 5

If the embodiment illustrated in Fig. 5 is in operation, the switch 83 (Fig. 4) may be closed to render the contacts KAI eifective and the switch 83A may be opened 19 to render the contacts K1 ineffective. In addition the switch 31 is opened to remove the bypass relay P from service. Insofar as practicable operations previously discussed for the system illustrated in Figs. -1 to 4 which are similar to the operations of the embodiment represented by Fig. will not be repeated.

It will be assumed initially that the elevator car is at the fifth floor set for down travel and that down calls are registered for the sixth and third floors. It will be assumed further that the elevator car is fully loaded at the fifth floor. As a result of such loading the switch BPA operates and opens its contacts to prevent energization thereth-rough of the floor-call stopping relay S. Consequently, during its return to the first floor the elevator car cannot stop in response to registered down floor calls.

In addition the operation of the switch BPA results in a momentary closure of the switch 89. Since the elevator car is positioned at the fifth floor momentarily closure of the switch 89 completes the following circuit:

-L+, 89, X7, 88, t5, 4P, L-

The bypass relay 4P opens its break contacts 4P1 and 4P2 and closes its make contacts 4P3 and 4P4 without immediately affecting the operation of the system. The closure of the make contacts 4P5 completes a self-holding circuit for the relay.

The elevator car now returns to the first floor, reverses and starts upwardly in the manner previously described. While the elevator car is at the first floor the switch 86 is open. However, inasmuch as the contacts SQAZ are closed, the relay 4P remains energized.

As the elevator car on its upward trip reaches the second floor the brush 85 engages the contact segment n2 to complete with the contact 4P4 and W12 an energizing circuit for the sequence relay SQA. This relay closes its holding contacts SQAl and opens its break contacts SQA-Z. However, since the mechanical switch 86 is now closed, the relay 4P remains energized.

When the brush 84 reaches the contact segments m3 the following circuit is completed:

L+, 4P3, 4on3, M3, 84, W11, KA, L

The high floor-call relay KA now closes its make contacts KAI (Fig. 4) to complete with the contacts M7, H1 and W7 an energizing circuit for the reversing relay I. This relay initiates the stopping and reversing of the elevator car at the third floor by a sequence which will be understood from the preceding discussion. From this brief analysis it will be seen that following the bypassing operation the elevator car reverses at the highest floor below the floor at which by bypassing started for which a down floor call is registered.

As the elevator car returns to the first floor, the cam 87 finally opens the mechanical switch 86. Since the contacts SQA2 are open, all of the bypass relays 3P to 6P must now be deenergized. As a result of its dropout the bypass relay 4? closes its make contacts 4P1 and 4P2 and opens its make contacts 4P3 and 4P5 without immediately affecting the operation of the system. Opening of the make contacts 4P4 deenergizes the sequency relay SQA and this relay now opens its make contacts SQAl and closes its break contacts SQAZ without immediately affecting the operation of the system. The elevator car then may proceed to the highest floor for which a call is registered.

Let it be assumed next that the elevator car bypassed at the fifth floor as in the preceding example that down floor calls are registered at the third and sixth floors and when the elevator car reached the first floor a passenger entered the elevator car and registered a car call for the seventh floor. The elevator car thereafter proceeds to the seventh floor to answer the car call by a sequence which will be understood from the foregoing discussion.

However, when the elevator car starts down, it is prevented from answering the down floor call registered at the sixth floor for the reason that the break contacts 4P1 are open. Consequently, the elevator car must travel express to a floor which is below the floor at which the elevator car started its bypassing operation on its preceding trip. Under the assumed conditions the elevator car consequently travels down until the brush 42 engages the contact segments g3 for the third floor. This completes an energizing circuit for the floor call stopping relay S and results in a stopping operation of the elevator car by a sequence which will be understood from the preceding discussion. After receiving its load from the third floor, the elevator car then may proceed to the first floor at which point the relays 4P and SQA reset in the manner previously described.

Consequently for the embodiment of Fig. 5 if an elevator car when set for down travel is forced to bypass at a floor it will proceed on its next up trip to the highest fioor below the floor at which it started to bypass for which a down floor call is registered. If the elevator car is forced to go above the floor at which it started a bypassing operation as a result of operation of a car call button, the elevator car A during its down trip will operate express to the highest floor below the floor at which it started its bypassing operation for which a down floor call is registered. In this way a reasonable distribution of service is provided for all floors of the building.

Although the invention has been described with reference to certain specific embodiments thereof, numerous modifications falling within the spirit and scope of the invention are possible.

I claim as my invention:

1. in an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floors, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service for each of the intermediate floors, start-initiating means efiective when in operated condition for initiating a starting operation of the elevator car from any of the floors at which the elevator car is stopped, direction-determining means for conditioning the elevator car for a first travel in a first direction at least to the farthest floor in the first direction for which a call for elevator service is registered by the call means, and transfer means responsive to occurrence of a predetermined condition for limiting the travel of the elevator car by stopping the elevator car when traveling in the first direction at one of the intermediate floors and reversing the direction of travel for which the elevator car is set even though a call is re istered by the call means at the time of such reversing for a fioor spaced in the first direction from the floor at which such reversing occurs, said transfer means being effective for the duration of said predetermined condition to assign the elevator car repeatedly for said first travel and for said limiting travel in accordance with a predetermined plan.

2. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floors, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable from each of the intermediate floors for registering calls for elevator service in a first direction, sec ond call means operable from each of the intermediate floors for registering calls for elevator service in a second direction, third call means operable for registering calls for floors desired by passengers within the elevator car, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered by the call means which may be answered by the elevator car without change in the direction of travel of the elevator car, start-initiating means effective when in operated condition for initiating a starting operation of the elevator car from any of the floors at which the elevator car is stopped, direction determining means for conditioning the elevator car for a first travel in a first direction at least to the farthest floor in the first direction for which a call for elevator service is registered by the call means, and transfer means responsive to occurrence of a predetermined condition for limiting the travel of the elevator car by stopping the elevator car when traveling in the first direction at one of the intermediate floors and reversing the direction of travel for which the elevator car is set even though a call is registered by the call means at the time of such reversing for a floor spaced in the first direction from the floor at which such reversing occurs, said transfer means being effective for the duration of said predetermined condition to assign the elevator car alternately for said first travel and for said limiting travel.

3. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floors, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service for each of the intermediate floors, start-initiating means efiective when in operated condition for initiating a starting operation of the elevator car from any of the floors at which the elevator car is stopped, direction-determining means for conditioning the elevator car for a first travel in a first direction at least to the farthest floor in the first direction for which a call for elevator service is registered by the call means, and transfer means responsive to occurrence of a predetermined condition for providing preferential elevator service for part only of. said elevator floors, said transfer means being effective for the duration of the predetermined condition to assign the elevator car repeatedly for said first travel and for said preferential elevator service in accordance with a predetermined plan.

4. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, one of said floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floors, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service for each of the intermediate floors, means effective while the elevator car is displaced from the parking ffoor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in first and second directions at least to the farthest floor in each direction for which a call is registered, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence 22 of a predetermined condition for providing preferential elevator service for part only of said intermediate floors.

5. In an elevator system, Li structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal fioors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, floors, third call means operable for registering calls for floors desired by passengers in the elevator car, means effective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest flor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence of a predetermined condition for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor for which a call is registered by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the last-named reversing floor.

6. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floors desired by passengers in the elevator car, means effective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means efi'ective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car Without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence of a predetermined condition for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor for which a call is registered by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the last-named reversing floor, said transfer means being responsive to a predetermined demand for elevator service in the second direction from floors displaced in the first direction from said last-named reversing floor for repeatedly initiating the first and second operation in accordance with a predetermined pattern for the duration of said predetermined demand.

7. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal fioors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floors desired by passengers in the elevator car, means etfective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence of a predetermined condition for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor for which a call is registering by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the lastnamed reversing floor, said transfer means being responsive to a predetermined loading of the elevator car in at least one direction of travel during said first operation for initiating said second operation.

8. In an elevator system, a structure having a pair of terminal fioors and a plurality of intermediate floors located between the terminal floors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floors desired by passengers in the elevator car, means efi'ective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of theelevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a fioor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence of a predetermined condition for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor which is the farthest floor in the first direction between the parking floor and a predetermined one of the intermediate floors for which a call is registered by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the predetermined one of the intermediate floors.

9. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, one of said floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floors, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service for each of the intermediate floors, means efiective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in first and second directions at least to the farthest floor in each direction for which a call is registered, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence of a predetermined condition for reducing the value of said substantial time at a predetermined one of said floors.

10. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floor desired by passengers in the elevator car, means elfective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, and transfer means responsive to occurrence of a predetermined condition for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor for which a call is registered by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the last-named reversing floor, said transfer means being responsive to occurrence of said predetermined condition for reducing the value of said substantial time for the parking floor.

11. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate fioors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floor desired by passengers in the elevator car, means effective while the elevator car is displaced from the parking floor for registering a call from the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, by-pass means operable for conditioning the elevator car to by-pass floors at which calls are registered by the second call means, and transfer means responsive to operation of the by-pass means while the elevator car is set for travel in the second direction for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor spaced in the second direction from the point at which said operation of the bypass means occurred for which a call is registered by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the last-named reversing floor.

12. In an elevator system, a structure having a pair of terminal doors and a plurality of intermediate floors located between the terminal floors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floor desired by passengers in the elevator car, means effective while the elevator car is displaced from the parking floor for registering a call for the parking floor, stopping means effective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest floor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not registered by the first call means, start-initiating means responsive to the expiration of a substantial time after the elevator car has stopped at a floor and to the presence of a call registered for another floor to initiate a starting operation of the elevator car, -by-pass means operable for conditioning the elevator car to by-pass floors at which calls are registered by the second call means, and transfer means responsive to operation of the by-pass means while the elevator car is set for travel in the second direction for initiating a second operation wherein the elevator car stops and reverses when traveling in the first direction at a floor spaced in the second direction from the point at which said operation of the by-pass means occurred for which a call is registered by the second call means even though a call is registered by the second call means for a floor displaced in the first direction from the last-named reversing floor, and means responsive to operation of said transfer means to initiate the second operation for reducing the value of said substantial time for the parking floor.

13. In an elevator system, a structure having a pair of terminal floors and a plurality of intermediate floors located between the terminal floors, one of said terminal floors being a parking floor, an elevator car, means mounting the elevator car for movement relative to the structure to serve the floor, motive means for moving the elevator car, and control means cooperating with the motive means to move the elevator car and to stop the elevator car at desired floors of the structure, said control means comprising first call means operable for registering calls for elevator service in a first direction from each of the intermediate floors, second call means operable for registering calls for elevator service in a second direction from each of the intermediate floors, third call means operable for registering calls for floor desired by passengers in the elevator car, means effective While the elevator car is displaced from the parking floor for registering a call for the parking fioc-r, stopping means eifective for stopping the elevator car at each floor approached by the elevator car for which a call is registered which may be answered by the elevator car without change in the direction of travel of the elevator car, direction-determining means for conditioning the elevator car for a first operation in a first direction away from the parking floor to the farthest fioor in the first direction for which a call is registered by the second and third call means and reversing the direction of travel of the elevator car provided a call from such farthest floor or for a floor beyond such farthest floor in the first direction is not 

